Self-opening die.



C. J. HARRINGTON.

SELF OPENING DIE. APPLICATION FILED MAR; 7. 1914.

1,154,568. PatentedSept.21,1915.

75'. H, Cilf farii 070 J CORNELIUS J. HARRINGTON, OF BOSTON,MASSACHUSETTS, ASSIGNORTO HARRINGTON MANUFACTURING COMPANY, OFMASSACHUSETTS.

Specification of Letters Patent.

BOSTON, MASSACHUSETTS, A CORPORATION OF SELF-OPENING DIE.

Patented Sept. 21, 1915;

Application filed March 7, 1914. Serial N0. 823,112.

To allwhom it may concern I Be it known that I, CORNELIUS J. HAR-RINe'roN, a citizen of the United States, and a resident of Boston, inthe county of Suffolk and State of Massachusetts, have invented certainnew and useful Improvements in Self-Opening Dies, of which the followingis a specification.

This invention has for its object to pro vide a quick-opening die whichmay be used for cutting screw threads, and particularly a die which maybe mounted upon a turret or carriage of a screw machine.

On the drawings, Figure 1 represents in front elevation a die embodyingthe invention. Fig. 2 represents a side elevation of the same. Fig. 3represents a longitudinal vertical section through the die. Fig. arepresents a section on the line l-4 of Fig. 3. Fig. 5 represents afront end elevation of the die with the sectional face plate removed.Fig. 6 shows one of the chasers. Fig. 7 represents one of the sectionsof the face plate. Fig. 8 shows a'section on the line 88 of Fig. 1, withthe chaser in end elevation. F ig. 9 shows the cam ring in position topermit the removal of the chasers without removing the face plate.

Referring to the drawings, the die body 10 has projecting from its rearface an elongated hub 11 by which it may be secured upon a turretindicated by dotted lines at 12. The hub is centrally apertured as shownat 13, and is providedwith a slot 14 the walls of which converge asshown in Fig. 4c for a purpose to be explained. From the front face ofthe die body, there are two annular flanges 15 and 16, there beingwithin the flange 15 a socket 16 to receive the work.

Placed in the annular groove 17 between the two flanges, there is a camring 18, having upon its front face cam ribs 19 for engagement with thechasers as will be explained. In the front ends of the flanges 15 and16, there are formed grooves 20 for the reception of chasers 21'. Incross section, said chasers are approximately oblong, and on each sideface of the chaser there'is a narrow rib '22, the slots QObeing soformed thatthe bottom of each is formed to receive one of said ribs.Each chaser is provided at each end with cutting edges. Said edges maybe formed so that, by reversing the chasers, right-hand or left-hand.threads'may be'cut upon the work, 'or else threads of different pitchmay be out according to the formation of the cutting edges onthe'chaserss Each chaser is provided on opposite sides with grooves 23to receive the cam ribs 19 on the cam ring 18. The chasers are held inplace by a front plate which is formed in a plurality of segmentalsections, each section being indicated at 24. The ends of the sect onsare separated and each end is undercut, as indicated at 25, to take overthe side of a chaser, as shown in Fig. 8, the faces of the ribs 22 beingflush with the exposed surfaces of the sections 24. The cutting edgesupon each chaser extends from face to face of the ribs '22 so that theend cutting edge on each chaser is flush with the exposed surface of thesection of theface plate. The sections of the face plate are secured tothe ends of the flanges 15 and 16 by screws or other fastenings 26, 2-7of Whichthere may be as many as needed.

The cam ring is moved to open position by a spring indicated at 28 whichbears at one end against an internal projection on the cam ring, and theother end of which bears against a shoulder in the die body. Said springis arranged in a groove behind the "cam ring. I have not deemed itnecessary to show the particular arrangement of this spring, it beingsufficient merely to state its function. a

The die body is formed with a segmental boss 30 having an arcuate groovein which is located a keeper 'block31 having curved I threaded ends321113011 which are located nuts 33 bearing against the side faces ofthe segmental boss. The keeper block 31 has a groove 34' to receive alatch 35 pivoted upon a pin 36 in a projecting arm 37 formed as a partof the cam ring 18. By swingingthe cam arm 37 in proper direction, asfor instance to the left in F ig. 1,'thecutters or chasers are forcedradially inwardly toward the work until the latch enters the notch 34 inthe keeper block 31, this movement being against the tension of thespring 28. By releasing the latch from the keeper block,

the spring 28 will rotate the cam ring in the opposite direction to openthe die automatically. I- provideautomatic means for releasing the latchfrom the keeper block. To this end, the arm 37 is formed at its end witha hub or bearing 38 for a slide bar 39 which is normally thrust to theleft by a spring 40 placed between the head 4.1 and a shoulder formed onthe hub. Preferably the hub is socketed to receive a portion of thespring.- The head 41 is provided with parallel ears 42 through which ispassed a pin 43, the latter also passing through a slot 44 in the end ofthe latch 35. This slot is preferably segmental and concentric with thepivot pin 36. The end of the slide bar 39 projects rearwardly from thebearing 38 and is threaded as shown for the purpose to be described.

I have already stated that the die body is provided with a centralaperture 13. In this aperture is located a spindle or member 24 which isadapted to slide and to rock therein. This spindle has a forwardlyprojecting pin 46 extending forwardly into the socket 16 in the centerof the die body and in line with the end of the work which is indicatedat a. Pivoted upon said pin 46 there is an arm 47 which extendsoutwardly through the slot 14, and the end of which is apertured as at48 to receive loosely the threaded end of the slide bar 39. Said arm 47and the spindle are adjustable longitudinally of the slide bar and aresecured after adjustment by nuts 49, 50 screwed on said threaded endsThe arm 47 is held against longitudinal movement relatively to the pin46 by a collar 51 secured to the said pin by a cross pin 52. The

collar 51 is of the same diameter as the spindle 45 so that it willslide in the aperture 13 in the die body. The tension of the spring 40is suflicient to hold the arm 47 against the rear face of the die body.In this connection, it will be observed from Figs. 3 and 4 that the rearportion of'the die is recessedas at 58, the walls of the recess beingrespectively in alinement with the converging walls of thegroove 14.-

In operation, when the chasers have advanced far enough upon the workfor the work to engage the pin 46, the continued 'movementof the diebody relatively to the work will cause the spindle 45 to be forcedrearwardly until the latch 35 has been disengaged from the keeper block,immediately upon which the spring 28 will rotate the cam ring 18 andopen the cutters or move them radially outwardly from the work. As thecam ring rotates, the arm 47 rotates with it until it engages the sidewall of the slot 14 or the side wall of the socket 53.

I-consider it to be a distinct advantage to have the face plate formedin segmental sections, as'it enables me to have the exposedfaces of thechasers flush with the plate or even toproject therebeyond if desired,as it is possible by this construction to force the chasers up to ashoulder on the work. so that the threads formed on the workwillterminate at the shoulder. Of course, where the screw threads are formedon a bar of relatively small diameter, this does not make so muchdifference, but, where the part to be threaded pro ects from ,a largebody portion, the construction is of great advantage for the reasongiven.

I have devised provisions by which the chasers may be removed andreversed or replaced without detaching the sectional face plate. By aninspection of Figs. 1 to 9, it will be seen that the cam ribs 19terminate at their outer portions in extremities or end portions 191which are radial of the axis of the die body. Hence the cam ring may berotated far enough to wholly disengage the said ribs from the chasers asshown in Fig. 9. Normally this extreme movement of the cam ring to theleft is prevented by a removable pin 60 (see Fig. placed in the path ofthe arm or handle 37. But by removing the pin, the cam ring may berotated sufficiently to the left to disengage the cam ribs from thechasers and permit the withdrawal of the latter. The member or spindle45 is held from rotation by a pin (31 which passes through a slot 62 inthe hub 11. A scale 63 is formed or secured on said hub, and an index isformed on the end of .the pin, so that the exact location of the end ofthe pin 46 in the die body may be determined and said pin set to beengaged by the work at the proper point after the dies have traveledalong the work. i

Having thus explained the nature ofmy' said invention and described away of making and using, the same, although without attempting to setforth. all of the forms in which it may be made or all of the modes ofits use, what I claim is:

.1. A self-opening die comprising a die body having a radially extendedsegment,

chasers mounted in said die body, a cam ring having means for operatingthe chasers,

a spring for rotating said cam ring to open the chasers, a latch carriedby. the cam ring e terlorly of the die body to lock the cam ring to thesegment on said die body, and

means for releasing the latch including a member centrally located inthe die body to be engaged by the work.

2. A self-opening die comprising a die body having a boss or segmentextending from its periphery, chasers mounted in said die body, a camring located in a groove on said die body and having means for operatingthe chasers, a spring for rotating said cam ring to open the chasers, alatch carried by the cam ring exteriorly of the die body to lock the camring to said boss or segment on the die body, a movable member arrangedin the die body to be engaged by the work, and connections between saidmember and the latch for releasing the latch.

3. A self-opening die comprising. a die body having a, boss or segmentextending from its periphery, chasers mounted in said die body, a camring in the die body having means for operating the chasers and alsohaving a radially extending arm, a spring for rotating said cam ring toopen the chasers, a latch carried by the arm of the cam ring exteriorlyof the die body to lock the ring to the boss or segment of the die bodywith the chasers in closed position, a member arranged in the axis ofthe die body and movable logitudinally, an arm projecting radially fromsaid member and adapted to oscillate thereabout, and a connectionbetween .said latch and said arm.

4. A self-opening die, comprising a die body, approximately radialchasers, a cam ring for operating said chasers, a spring for partiallyrotating said ring to open the chasers, an adjustable keeper on the diebody, a latch carried by the cam ring toengage said keeper and hold thechasers in closed position, a longitudinally movable member located inthe die body in line with the work, a slide carried by the cam ringexteriorly of the die body for operating said latch, and means rotatablewith the cam ring and connecting said slide and said member.

5. A self-opening die, comprising a die body, approximately radialchasers, a cam ring for operating said chasers, a spring for partiallyrotating said ring to open the chasers, a keeper on the die body, alatch pivoted to the cam ring to engage the keeper and hold the chasersin closed position, a slide movable longitudinally of the die body andmounted on the cam ring exteriorly of said die body, a pin and slotconnection between the latch and the slide, and Workoperated means formoving said slide to release the latch.

6. A self-opening die, comprising a die body, approximately radialchasers, a cam ring for operating said chasers, a spring for partiallyrotating said ring to open the chasers, an arm projecting radially fromsaid cam ring, a latch pivoted to said arm and a keeper block on the diebody for locking the cam ring to the die body, a slide on the armparallel to the axis of the die body, a work-engaging member in the diebody, and an arm pivoted thereto for moving said slide to release thelatch and permit the spring to open the chasers. V

7. A self-opening die, comprising a die body, approximately radialchasers, a cam ring for operating said chasers, a spring for partiallyrotating said ring to open the chasers, an arm projecting radially fromsaid cam ring, a latch pivoted to said arm and a keeper on the die bodyfor locking the cam ring to the die body, a slide on the arm parallel tothe axis of the die body, a member in the die body to be engaged by thework, an oscillatory arm secured to said member and projecting radiallytherefrom, and means for adjustably connecting said arm to said slide.

8. A die comprising a body having substantially radial guideways,reversible chasers in said guideways having ribs on their side faces andgrooves in their front and rear faces, a cam ring having cams forengagement with said grooves, and a face plate formed of segmentalsections secured to said die body, the ends of said sections overlappingsaid chasers, with the exposed faces of the said ribs substantiallyflush with the exposed face of said face plate.

9. A die comprising a body having substantially radial guideways,chasers in said guideways having ribs on their side faces, and a faceplate formed of segmental sections secured to said die body, the ends ofsaid sections overlapping said chasers, with the exposed faces of thesaid ribs substantially flush with the exposed face of said face plate,each ofsaid chasers having cutting edges on both ends, extending to theexposed surface of the ribs on said chaser.

10. A self-opening die comprising a die body, having approximatelyradial guide-- ways, chasers in said guideways having grooves in theirsides, aface plate confining said chasers in said guideways, anoscillatory cam ring mounted within said guideway and having cam ribsfor moving said chasers, a spring for moving said cam to open thechasers, said cam ring having a radial arm, and a stop normally locatedin a socket in the die body in the path of said arm for normallystopping the movement of the cam ring while said ribs are in engagementwith the chasers, said ribs terminating at points which permit thedisengagement of said ribs from said chasers when said cam ring isrotated beyond its normal limit of movement upon the removal of saidstop pin.

In testimony whereof I have afiixed my signature, in presence of twowitnesses.

CORNELIUS J. HARRINGTON. Witnesses: 7

JOHN J. HAGERTY, JOHN P. MURRAY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

